Hydraulic boom for earth excavating apparatus

ABSTRACT

A boom for earth excavating apparatus comprises a first elongated tubular shaped member, a second elongated tubular shaped tool supporting member positioned within the first member and adapted for telescoping movement therein, a hydraulic cylinder positioned within the outer boom member, means for constraining motion of the cylinder in a longitudinal direction with respect to the outer boom member, a hydraulic piston positioned within the cylinder and coupled to the second member for causing longitudinal motion of the second tubular member when a hydraulic force is applied thereto, means intercoupling the cylinder and the second boom member for guiding motion of said second member in a longitudinal direction and for causing rotation about a longitudinal axis thereof when the cylinder is rotated, and means for providing rotation of the cylinder thereby causing rotation of the second member and the tool about a longitudinal axis.

United States Patent Beaton 541 HYDRAULIC BOOM FOR EARTH EXCAVATING APPARATUS [72] Inventor: Joseph R. Benton, Hillside Terrace,

Oneida, NY. 13403 22 Filed: Aug. 16,1971

[21 Appl.No.: 171,901

[52] us. c1 "214/141, 212/55 581 FieldotSearch'.. ..214/l4l,135,'l36,137; 212/55;92/31,32;91/61 [56] 7 References Cited 1 UNITED sTATEs PATENTS 3,042,234 7/1962 Davis ..214/141 3,069,033 12/1962 Ferwerda... 4214/141 Primary Examiher Albert J. Makay Assistant Examiner-John Mannix Attorney-William Kaufman et al.

Przybylski; 214/141 Oct. 24, 1972 v ABSTRACT A boom for earth excavating apparatus comprises a first elongated tubular shaped member, a second elongated tubular shaped tool supporting member positioned within the first member and adapted for telescoping movement therein, a hydraulic cylinder positioned within the outer boom member, means for constraining motion of the cylinder in a longitudinal direction with respect to the outer boom member, a hydraulic piston positioned within the cylinder and coupled to the second member for causing longitudinal motion of the second tubular member when a hydraulic force is applied thereto, means intercoupling the cylinder and the second boom member for guiding motion of said second member in alongitudinal direction and for causing rotation about a longitudinal axis thereof 1 when the cylinder is rotated, and means for providing rotation of the cylinder thereby causing rotationof the second member and the tool about a longitudinalaxis. I 7 Claims, 7 Drawing Figures- PATENTEU BET 24 I973 3.7 00. 1 26 sum 1 or 2 I v [NI/6N 1'01? Joseph R. Bea ion BY 3M0! 54 firm/wa s.

PATENTEDUCI 24 I972- SHEET 2 BF 2 HYDRAULIC BOOM FOR EARTH EXCAVATING APPARATUS This invention relates to earth excavating apparatus. The invention relates more particularly to an improved arrangement for operating an excavating tool which is employed with earth excavating apparatus.

In various types of construction equipment, an earth excavating tool such as a scoop or a bucket is mounted on, and, is operated from a self-propelled vehicle. The tool is generally supported near the end of an elongated boom which is mounted on the vehicle and which can provide motion of the tool in various directions. In providing this motion, it is desirable that the boom be extensible along its longitudinal axis and that it be rotatable about this axis. Heretofore, motion of the boom along a longitudinal axis has been accomplished by providing a first boom member and a second boom member to which the tool is mounted and which is telescopically movable with respect to the first boom member. Motion about the longitudinal axis has been previously accomplished in one arrangement by another arrangement, a telescopic boom member is rotated with respect to an outer boom member through the use of a chain and sprocket drive wherein a drive chain is coupled to the extensible boom member for rotation of this member. These techniques suffer from the disadvantage of mechanical complexity resulting in increased maintenance time and cost of operation.

A hydraulic control system is generally provided for operating the telescoping boom member and for causing deflection of the tool during an excavating operation. The various motions of the excavating tool have heretofore necessitated the use of flexible hydraulic lines for interconnecting the various hydraulic system elements. As a result, the hydraulic lines to actuating elements of the hydraulic system have been relatively long, and susceptible to damage thereby resulting in frequent down time for the apparatus.

Accordingly, it is an object of this invention to provide an improved earth moving apparatus.

Another object of the invention is to provide an improved boom arrangement for an earthmoving apparatus.

Another object of the invention is to provide improved means for effecting rotation of an excavating tool about a longitudinal axis of a supporting boom.

Another object of the invention is to provide a telescoping boom assembly having an improved means for rotating the excavating tool about a longitudinal axis.

Still another object of the invention is to provide a telescoping boom assembly having a rotatable inner boom member and, an improved means for supporting and rotating the inner boom member about a longitudinal axis.

A further object of the invention is to provide an improved means for applying hydraulic pressure to the operating elements of a hydraulic system in an earth moving apparatus.

Another object of the invention is to provide an improved arrangement for conveying hydraulic fluid over an elongated path in a boom having an inner telescoping and rotatable boom member.

In accordance with the general features of this invention, a boom for earth moving apparatus is provided comprising a first elongated tubular shaped member, a second elongated tubular shaped tool supporting member positioned within the first member and adapted for telescoping movement therein, a hydraulic cylinder positioned within the outer boom member, means for constraining motion of the cylinder in a longitudinal direction, a piston positioned within the cylinder and coupled to the second member for causing longitudinal motion of the second tubular member in response to a hydraulic pressure applied to the piston, means intercoupling the cylinder and the second boom member for guiding longitudinal motion of said second member and for causing rotation about a longitudinal axis thereof when the cylinder is rotated, and means for providing rotation of the cylinder thereby causing rotation of the second member and the tool about a longitudinal axis.

In accordance with more particular features of the invention, the hydraulic cylinder comprises an elongated body having splines spaced about its outer surface and extending longitudinally along the surface thereof. Means are positioned-in engagement with the splined surface of this cylinder and with the second elongated tubular shaped member in a manner for causing rotation of the tubular member as the cylinder is rotated and for providing a bearing surface for the tubular member. Rotating drive means are mechanically coupled to the cylinder for rotating the cylinder and for causing the second elongated tubular shaped body which is mechanically coupled thereto to rotate. The means for mechanically intercoupling the splined outer surface of the cylinder and the second tubular body includes a demountable bearing surface which is replaceable after extended wear. In accordance with another feature of the invention, the splines extending along the length of the cylinder include internal channels for conveying hydraulic fluid along the length of the cylinder between a source of hydraulic fluid and operable members of the hydraulic system.

These and other objects and features of the invention I will become apparent with reference to the following specification and to the drawings wherein:

FIG. 1 is a perspective view of an earth moving ap paratus mounted on a wheeled vehicle and constructed in accordance with features of this invention;

FIG. 2 is'a side elevational view of a boom arrangement of FIG. 1;

FIG. 3 is a sectional view of the boom arrangement of FIG. 2;

FIG. 4 is a sectional view taken along lines 4-4 of FIG. 3;

FIG. 5 is a sectional view taken along lines 5-5 of FIG. 3;

FIG. 6 is a sectional view taken along lines 66 of FIG. 3; and

FIG. 7 is an enlarged view of a bearing assembly of FIG. 3.

Referring now to FIGS. 1 and 2, an earth moving apparatus is shown to include a vehicle 8 upon which is mounted a first cylindrically shaped outer boom member 10 which is supported in a cradle 12. The crapiston and cylinder units 16 and 17. The platform is positioned on the wheeled vehicle 8 for transport from location to location. Alternatively, the vehicle may comprise a tracked'type vehicle. An earth excavating tool 20 is pivotally supported at a distal segment of a second elongated, tubular shaped, telescoping boom member 22 which extends from the first boom member 10. The tool 20 is rotated about a support pin 23 by a piston 24 which extends from a tool control cylinder 25.

The boom assembly comprises in addition to the outer tubular shaped boom member 10 and the inner tubular shaped boom member 22, a hydraulic actuating system [FIGS. 3-6] including a piston 29 and cylinder 30 for causing'telescopic motion of the inner boom 22 within the outer boom 10, a means for constraining longitudinal motion of the cylinder 30, a means for mechanically intercoupling'the cylinder 30 and the inner boom member 22, and a means for causing rotation of the cylinder 30 thereby causing rotation of the inner boom member 22 within the outer boom member 10. The cylinder 30 comprises an elongated barrel having a bore extending longitudinally through the barrel and which is adapted for receiving the, piston 29 to which a piston rod 34 is connected; A rearward portion of the barrel'30 tapers to an integral ball shaped segment 36 from which" a conduit 38 extends'and communicates with a hydraulic fluid collector block 40. A plurality ofbearing races 42 are positioned about the ball shaped segment 32 and are secured about the segment and maintained in position by a mounting block 44 which is bolted to a rear wall 46 of the outer boom -4 inner boom member 22 thereby restraining any motion of the pin 54 tending to withdraw the pin from the groove in the block 56. Thus, the piston is coupled to.

the inner boom member 22 and as the piston 32 moves longitudinally within the cylinder 30, a telescoping motion of the inner boom member within the outer boom member occurs.

r A .means for providing mechanical engagement between the cylinder and the inner boom member 22 includes a plurality of splines or rails 64 which are integrally formed on an outer surface of he cylinder 30. A generally tubular shaped body 66 is concentrically positioned within the boom member 22 and is mounted, by welding for example, to an inner surface of the boom member 22. The innersurface of the body 66 also includes splines or rails 68 extending radially toward the cylinder 30. An elongated generally tubular shaped .bushingbody 70 is coaxially positionedwith the body 66 and the lower member 22 as the member '10. The cylinder 30 is thereby constrained,

from longitudinal motion within the outer boom member 10 butv can .be rotated about the ball shaped .through a hydraulic fluidseal 50 positioned in an aperture of this block. An aperture 52 is formed in the piston rod 34 near a distal segment thereof through which a pin 54 extends. The pin 54' couples an activating force from the piston rod 34 to an inner wall of the boom member 22. The pin is secured to the member 22 at one end of the pin by;blocks 56 and 58 [FIG.' 6] which are positioned at the inner surface of the boom member 22 and is secured to the member 22 at another diametrically opposite location by a similar pair of blocks which are also positioned at the inner surface of the boom member 22. The block 56 includes a groove 59 extending circumferentially through a portion of the body. This block is screw mounted to the inner wall of member 22 and the pin 54 is located in the grooveby slightly rotating the shaft 34 in a manner for providing that the pin engages the groove and is twisted to a stop position within the groove. The other end of the pin similarly engages a grooved block at the opposite inner surface of member 22. Block 58 is then bolted to the piston 29 causes motion of this boom member. The bushing which provides sliding contact between the boom member 22 and-the cylinder 30 comprises a demountable wearing su'rfacewhich can be'replaced after extended use and wear. When rotary motion is imparted'to the cylinder30 as discussed hereinafter, engagement provided between the cylinder 30 and the boom member 22 by virtue-of the splines 64 on the outer surface of the cylinder 30, the grooves of bushing member 70, and the splines on plate 66 cause a corresponding rotary mo'tion of the' inner boom member 66 aboutalongitudinal axis 71. l

A means for providing rotary motion of the cylinder 30 about the'longitudinal axis 71 includes a spur gear mounted to the cylinder 30 and hydraulic motors which engage the spur gear. The spur gear-comprises simi-circular gear segments 72 and 74 [FIG. 4] which are positioned about the outer surface of the cylinder 30 at a rearward portion thereof and which are mounted to the cylinder by screws 76. A pair of hydraulic motors 78 i and are positioned adjacent an inner surface of the boom member 10 and are mounted to a wall of this member. These motors each include a drive spur gear which engage the spur gear mounted to the cylinder 30. The hydraulic motors 78 and 80 which are of a conventional type are accessible through doors 79 and are arranged to simultaneously rotate in opposite directions when energized in order to cause rotation of the cylinder 30 in a desired direction as viewed in FIG. 4. Reversal in the direction of rotation of these motors will cause rotation of the cylinder 30 in an opposite direction The motors are controlled by conventional hydraulic control systems and are energized by hydraulic feed lines (not shown) which are coupled to the motors. I

During motion of the inner boom member 22 within the outer boom member10 in a longitudinal direction,

a sliding contact is provided between the member 22 and the hydraulic cylinder 30 by the bushing member 70, as has been indicated. In order to reduce the frictional engagement between the outer surface of boom member 22 and the inner surface of boom member 10, a stationary ball bearing assembly is positioned near a forward segment of the outer member and a transported ball bearing assembly is mounted to the inner boom member 22 and travels therewith for contact with the inner surface of the outer boom member 10. The stationary bearing assembly includes a plurality of apertures 81 which are formed in the outer boom member 10 are are equally spaced about its circumference. A ball bearing race 82 is positioned in each of these apertures and a ball bearing 84 extends through the race and aperture to contact an outer surface of the member 22. The bearings are secured in place by a bearing race 86 which extends around the outer boom member 10. The race 86 is secured in place by a plate 88 which is bolted to the outer boom member 10. The

ball bearings 84 function both to provide a low friction sliding engagement with the outer surface of inner boom member 22 and to center this boom member.

A similar bearing arrangement is provided and mounted at an inner end of the boom member 22. A plurality of apertures are formed in the wall of member 22 about its circumference for receiving ball bearings 90 and associated races 92. The ball bearings extend through the races and apertures in the inner boom member 22 and contact the inner surface of the outer boom member 10. An annular shaped race 94 [FIG 7] is provided for positioning the ball bearings. The race 94 tapers to a greater thickness near an outer edge thereof and is adapted for receiving bolts 95 for mounting this race to the plate 66. Longitudinal adjustment of the bolts 95 will control the position of the race 94 and the amount of extension of the ball bearings from the apertures and thus provides a spacing adjustment between the inner and outer booms.

Hydraulic fluid pressure for operating piston 29 in order to cause telescoping motion of the inner boom member 22 and for operating the piston 24 in order to cause rotation of the excavating tool is applied to the boom through inlet lines 96, 98, 100 and 102. These lines supply hydraulic fluid to an oil separator 104 contained within the collector block 40. The oil separator 104 includes three sectors each of which directs oil to a one of three oil chambers which are formed in the constructed end of the hydraulic cylinder 30. These three separate oil chambers communicate with associated hydraulic fluid channels 106, 108 and 100 which are formed in and extend through the splines of the cylinder 30. Three separate flow paths are thereby provided for conducting hydraulic fluid along the length of the cylinder to the forward end of the cylinder 30. The block 48, referred-to-hereinbefore, and which is mounted to the front end of the cylinder 30 includes channels formed therein which communicate with the member 22 within the outer boom member 10. Extension of the inner boom member 22 is caused by hydraulic forces established on the left side of the piston 29. The hydraulic fluid flow paths for applying this force extend from the inlet hose 96 through hollowed portions of the neck 38, through the ball 42 and through the tapered segment of the chamber 30 into the left side of the cylinder 30.

Operation of the tool about its pivot point is effected by hydraulic pressure coupled to the tool control cylinder [FIG. 2] from channels 108 and 110 in the cylinder 30. Channels 112 and 114 are formed in the block 48 and communicate with the channels 108 and 110 respectively in the cylinder for conveying hydraulic fluid to outlet fittings 116 and 118 respectively. These fittings are coupled by appropriate flexible hydraulic lines (not shown) to the tool control cylinder 25 (FIG. 2) for establishing hydraulic forces on opposite sides of a piston positioned within this 1 cylinder in order to cause extension or retraction of the channels 106, 108 and 110. A first of the channels in piston 24 and thereby cause rotation of the tool 20 about its pivot point. Controls for selectively applying fluid pressure to either of the lines 96 through 102 are provided by conventional hydraulic fluid controls which are located convenient to the operator of the earth moving apparatus. A cover body 122 extends about the oil collector block and is secured to the outer boom member 10 by screws.

There has thus been described an improved boom arrangement for an earth moving apparatus wherein the tool is adapted to be rotated about a longitudinal axis of a telescoping boom in a convenient and relatively noncomplex manner. Furthermore, the inner boom can advantageously be rotated about a longitudinal axis and by virtue of the use of the single cylinder described.

While I have illustrated and described particular embodiments of my invention, it will be understood that various modifications may be made therein without departing from the spirit of the invention and the scope of the appended claims.

What is claimed is:

1. A boom for an earth excavating apparatus comprising:

a first elongated tubular shaped member;

a second elongated tubular shaped tool supporting member positioned within said first member;

a hydraulic cylinder mounted within said first boom member;

means for constraining motion of said cylinder in a longitudinal direction with respect to said first member;

a hydraulically operated piston positioned within said cylinder and coupled to said second member for causing longitudinal motion of said second member;

means intercoupling said cylinder and said second boom member for guiding motion of said second member in a longitudinal direction and for causing rotation about a longitudinal axis thereof when said cylinder is rotated; and,

means for causing rotation of said cylinder to thereby provide rotation of said second member about a longitudinal axis.

2. The boom of claim 1 wherein said means for intercoupling said cylinder and said second boom member includes a plurality of splines extending longitudinally on an outer surface of said hydraulic cylinder, and means are coupled to an inner surface of said second member for engaging said splines.

3. The boom of claim 2 wherein said means coupled to the inner surface of said second member includes a plate secured to the inner surface of said second boom member and a bearing body positioned between and engaging said plate and the splined surface of said hydraulic cylinder.

4. The boom of claim 3 wherein said bearing body insecond boom member and an inner surface of said first boom member comprising a stationary ball bearing arrangement secured to the outer boom member and a moveable ball bearing arrangement secured to an inner extremity of said second boom member.

6. The boom of claim 1 wherein said means for constraining said cylinder with respect to said first boom member comprises a generally ball shaped segment positioned near an extremity of said cylinder and means secured to said first boom member for rotatably engaging said ball shaped segment.

7. The boom of claim 4 wherein said splines formed in the outer surface of said cylinder include a hydraulic fluid channel formed therein for conducting hydraulic fluid along a portion of the length of said cylinder.

Beatenl PO-ww UMTED STATES mire-1t TUFFICEJ I t @EETM @EF. bitiiibifi Patent No. 3,7oo,-126 v Dated October 24, 1972 Inventnfls-X) Joseph R. Beaton It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

fiolumn 5, line 53., "constructed" should be -constricted-.

Column 4, line ll, 'he" should be the.

Column 2, line 48, "specification" should be --'-s; ecifications- Signed and sealed this 29th day of May 1973.

(SEAL) Attest:

EDWARD M.PLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents 

1. A boom for an earth excavating apparatus comprising: a first elongated tUbular shaped member; a second elongated tubular shaped tool supporting member positioned within said first member; a hydraulic cylinder mounted within said first boom member; means for constraining motion of said cylinder in a longitudinal direction with respect to said first member; a hydraulically operated piston positioned within said cylinder and coupled to said second member for causing longitudinal motion of said second member; means intercoupling said cylinder and said second boom member for guiding motion of said second member in a longitudinal direction and for causing rotation about a longitudinal axis thereof when said cylinder is rotated; and, means for causing rotation of said cylinder to thereby provide rotation of said second member about a longitudinal axis.
 2. The boom of claim 1 wherein said means for intercoupling said cylinder and said second boom member includes a plurality of splines extending longitudinally on an outer surface of said hydraulic cylinder, and means are coupled to an inner surface of said second member for engaging said splines.
 3. The boom of claim 2 wherein said means coupled to the inner surface of said second member includes a plate secured to the inner surface of said second boom member and a bearing body positioned between and engaging said plate and the splined surface of said hydraulic cylinder.
 4. The boom of claim 3 wherein said bearing body includes grooves for engaging splines formed on the outer surface of said cylinder and grooves for engaging a plurality of splines formed on an inner surface of said plate.
 5. The boom of claim 4 including means for reducing frictional contact between an outer surface of said second boom member and an inner surface of said first boom member comprising a stationary ball bearing arrangement secured to the outer boom member and a moveable ball bearing arrangement secured to an inner extremity of said second boom member.
 6. The boom of claim 1 wherein said means for constraining said cylinder with respect to said first boom member comprises a generally ball shaped segment positioned near an extremity of said cylinder and means secured to said first boom member for rotatably engaging said ball shaped segment.
 7. The boom of claim 4 wherein said splines formed in the outer surface of said cylinder include a hydraulic fluid channel formed therein for conducting hydraulic fluid along a portion of the length of said cylinder. 